Auxiliary Power Unit Apu Compartment

An auxiliary power unit apu is a device on a vehicle that provides energy for functions other than propulsion they are commonly found on large aircraft and naval ships as well as some large land vehicles.

Auxiliary power unit apu compartment.

If the apu egt reaches 620 650 c the bleed air valve will modulate toward. It also provides pneumatic power for the environmental control system ecs and for main engine starting on the ground and in flight up to 30 000 feet. Because of these limits the apu may only power one bus in the air. The purpose of the ejector is to ensure t hat a steady fl ow of air.

A typical apu compartment. The generator is rated at 30 kva and produces 115 vac electrical power for backup to the main engine generators refer to chapter 7. The apu is a compact self contained unit that provides compressed air for engine starting on the ground. The apu compartment is by definition a fire zone see fig.

Standardized definitions of safety significant propulsion system and auxiliary power unit apu malfunctions and rationale for definition changes from the first report. Automatic shutdown of the apu. However if you should accidentally take off with the apu on the busses then it will continue to power both busses. Others can produce 28 v.

The airborne auxiliary power is obtained from a gas turbine auxiliary power unit apu. The auxiliary power unit apu is installed within a fireproof titanium enclosure in the aft equipment compartment. Automatic shutoff of air source. It is isolated from the rest of the airplane by a firewall.

Auxiliary power unit rev 41 jul 08 2004 flight crew operating manual. Aircraft apus generally produce 115 v alternating current ac at 400 hz rather than 50 60 hz in mains supply to run the electrical systems of the aircraft. The auxiliary power unit apu is a honeywell gas turbine hgt400 g. For apu operating limitations refer to the flight crew operating manual fcom csp 700 6 vol 1 chapter 2 limitations.

Operation and control of the apu electric and bleed system is performed at the electrical and bleed air conditioning anti ice panel respectively. The unit provides compressed air for air conditioning while the airplane is on the ground and at limited altitude in flight. The galley power will automatically be load shed if the apu load reaches 165a. The hgt400 g provides an alternate source of electrical power on the ground and in flight to 45 000 feet.

Standardized definitions of propulsion system and apu related aircraft hazard levels based on the consequences to the aircraft passengers and crew and rationale for. The apu is a fully automated gas turbine power plant which drives an electrical generator.